exports.doNothing = doNothing;
function doNothing() {}

exports.hasKeys = function(object) {
    for (var key in object) return true;
    return false;
};

// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/isInteger#Polyfill
exports.isInteger =
    Number.isInteger ||
    function(value) {
        return typeof value === 'number' && isFinite(value) && Math.floor(value) === value;
    };

exports.isValidVersion = function(version) {
    if (version === null) return true;
    return exports.isInteger(version) && version >= 0;
};

exports.isValidTimestamp = function(timestamp) {
    return exports.isValidVersion(timestamp);
};
